In real-time and open systems, such as monitoring systems in a hospital or a power grid, modules are plugged into the system and moved at run time. One goal when a new module is plugged into a system is that the module may need to be able to deliver data in a fixed amount of time. Some middleware standards allow applications to request quality of service. However, there is no mechanism in the middleware to guarantee such quality of service.
Another example of message based quality of service is differentiated service in IP networks where quality of service parameters can be inserted by applications in IP headers. However, there is no guarantee how routers in the network will treat packets marked with such quality of service parameters.
Another issue that exists with open networks where an application can specify its own quality of service is that bad actors can disrupt network quality of service provided to other actors. For example, an application infected with a virus could specify high quality of service for all of its packets, which may result in service degradation for other applications in the network.
In light of these difficulties, there exists a need for improved enabling of real time guarantees in publish-subscribe middleware using dynamically reconfigurable networks.